Class UndirectedGraph<V>

java.lang.Object
cloud.opencode.base.graph.UndirectedGraph<V>
Type Parameters:
V - the vertex type | 顶点类型
All Implemented Interfaces:
Graph<V>
public class UndirectedGraph<V> extends Object implements Graph<V>
Undirected Graph 无向图

Implementation of an undirected graph using adjacency list.

使用邻接表实现的无向图。

Features | 特性:

  • Thread-safe (uses ConcurrentHashMap) | 线程安全（使用ConcurrentHashMap）
  • Supports weighted edges | 支持加权边
  • Bidirectional edge storage | 双向边存储

Usage Examples | 使用示例:

Graph<String> graph = new UndirectedGraph<>();
graph.addEdge("A", "B");
// Both A->B and B->A are created
Set<String> aNeighbors = graph.neighbors("A");  // ["B"]
Set<String> bNeighbors = graph.neighbors("B");  // ["A"]

Security | 安全性:

  • Thread-safe: Yes (uses ConcurrentHashMap) - 线程安全: 是（使用ConcurrentHashMap）
  • Null-safe: Yes (rejects null vertices) - 空值安全: 是（拒绝null顶点）
Since:
JDK 25, opencode-base-graph V1.0.0
Author:
Leon Soo www.LeonSoo.com
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    UndirectedGraph()
    Create an empty undirected graph 创建空的无向图

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addEdge(V from, V to)
    Add an unweighted edge 添加无权重边
    void
    addEdge(V from, V to, double weight)
    Add a weighted edge 添加加权边
    void
    addVertex(V vertex)
    Add a vertex to the graph 添加顶点到图
    void
    clear()
    Clear the graph 清空图
    boolean
    containsEdge(V from, V to)
    Check if the graph contains an edge 检查图是否包含边
    boolean
    containsVertex(V vertex)
    Check if the graph contains a vertex 检查图是否包含顶点
    int
    edgeCount()
    Get the number of edges 获取边数量
    Set<Edge<V>>
    edges()
    Get all edges 获取所有边
    double
    getWeight(V from, V to)
    Get the weight of an edge 获取边的权重
    Set<Edge<V>>
    inEdges(V vertex)
    Get incoming edges to a vertex 获取顶点的入边
    boolean
    isDirected()
    Check if this is a directed graph 检查是否为有向图
    Set<V>
    neighbors(V vertex)
    Get neighboring vertices 获取邻接顶点
    Set<Edge<V>>
    outEdges(V vertex)
    Get outgoing edges from a vertex 获取顶点的出边
    void
    removeEdge(V from, V to)
    Remove an edge 移除边
    void
    removeVertex(V vertex)
    Remove a vertex and all its edges 移除顶点及其所有边
    String
    toString()
     
    int
    vertexCount()
    Get the number of vertices 获取顶点数量
    Set<V>
    vertices()
    Get all vertices 获取所有顶点

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    Methods inherited from interface Graph

    inDegree, isEmpty, outDegree, snapshot

  • Constructor Details

    • UndirectedGraph

      public UndirectedGraph()
      Create an empty undirected graph 创建空的无向图

  • Method Details

    • addVertex

      public void addVertex(V vertex)
      Description copied from interface: Graph
      Add a vertex to the graph 添加顶点到图
      Specified by:
      addVertex in interface Graph<V>
      Parameters:
      vertex - the vertex to add | 要添加的顶点

    • addEdge

      public void addEdge(V from, V to)
      Description copied from interface: Graph
      Add an unweighted edge 添加无权重边
      Specified by:
      addEdge in interface Graph<V>
      Parameters:
      from - the source vertex | 源顶点
      to - the target vertex | 目标顶点

    • addEdge

      public void addEdge(V from, V to, double weight)
      Description copied from interface: Graph
      Add a weighted edge 添加加权边
      Specified by:
      addEdge in interface Graph<V>
      Parameters:
      from - the source vertex | 源顶点
      to - the target vertex | 目标顶点
      weight - the edge weight | 边权重

    • removeVertex

      public void removeVertex(V vertex)
      Description copied from interface: Graph
      Remove a vertex and all its edges 移除顶点及其所有边
      Specified by:
      removeVertex in interface Graph<V>
      Parameters:
      vertex - the vertex to remove | 要移除的顶点

    • removeEdge

      public void removeEdge(V from, V to)
      Description copied from interface: Graph
      Remove an edge 移除边
      Specified by:
      removeEdge in interface Graph<V>
      Parameters:
      from - the source vertex | 源顶点
      to - the target vertex | 目标顶点

    • vertices

      public Set<V> vertices()
      Description copied from interface: Graph
      Get all vertices 获取所有顶点
      Specified by:
      vertices in interface Graph<V>
      Returns:
      set of vertices | 顶点集合

    • edges

      public Set<Edge<V>> edges()
      Description copied from interface: Graph
      Get all edges 获取所有边
      Specified by:
      edges in interface Graph<V>
      Returns:
      set of edges | 边集合

    • neighbors

      public Set<V> neighbors(V vertex)
      Description copied from interface: Graph
      Get neighboring vertices 获取邻接顶点
      Specified by:
      neighbors in interface Graph<V>
      Parameters:
      vertex - the vertex | 顶点
      Returns:
      set of neighboring vertices | 邻接顶点集合

    • outEdges

      public Set<Edge<V>> outEdges(V vertex)
      Description copied from interface: Graph
      Get outgoing edges from a vertex 获取顶点的出边
      Specified by:
      outEdges in interface Graph<V>
      Parameters:
      vertex - the vertex | 顶点
      Returns:
      set of outgoing edges | 出边集合

    • inEdges

      public Set<Edge<V>> inEdges(V vertex)
      Description copied from interface: Graph
      Get incoming edges to a vertex 获取顶点的入边
      Specified by:
      inEdges in interface Graph<V>
      Parameters:
      vertex - the vertex | 顶点
      Returns:
      set of incoming edges | 入边集合

    • vertexCount

      public int vertexCount()
      Description copied from interface: Graph
      Get the number of vertices 获取顶点数量
      Specified by:
      vertexCount in interface Graph<V>
      Returns:
      vertex count | 顶点数量

    • edgeCount

      public int edgeCount()
      Description copied from interface: Graph
      Get the number of edges 获取边数量
      Specified by:
      edgeCount in interface Graph<V>
      Returns:
      edge count | 边数量

    • containsVertex

      public boolean containsVertex(V vertex)
      Description copied from interface: Graph
      Check if the graph contains a vertex 检查图是否包含顶点
      Specified by:
      containsVertex in interface Graph<V>
      Parameters:
      vertex - the vertex to check | 要检查的顶点
      Returns:
      true if contains | 如果包含返回true

    • containsEdge

      public boolean containsEdge(V from, V to)
      Description copied from interface: Graph
      Check if the graph contains an edge 检查图是否包含边
      Specified by:
      containsEdge in interface Graph<V>
      Parameters:
      from - the source vertex | 源顶点
      to - the target vertex | 目标顶点
      Returns:
      true if contains | 如果包含返回true

    • getWeight

      public double getWeight(V from, V to)
      Description copied from interface: Graph
      Get the weight of an edge 获取边的权重
      Specified by:
      getWeight in interface Graph<V>
      Parameters:
      from - the source vertex | 源顶点
      to - the target vertex | 目标顶点
      Returns:
      the edge weight, or Double.MAX_VALUE if no edge exists | 边权重，如果边不存在则返回Double.MAX_VALUE

    • isDirected

      public boolean isDirected()
      Description copied from interface: Graph
      Check if this is a directed graph 检查是否为有向图
      Specified by:
      isDirected in interface Graph<V>
      Returns:
      true if directed | 如果是有向图返回true

    • clear

      public void clear()
      Description copied from interface: Graph
      Clear the graph 清空图
      Specified by:
      clear in interface Graph<V>

    • toString

      public String toString()
      Overrides:
      toString in class Object